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Aspicilia arctica (Lynge) Oksner
Family: Megasporaceae
[Lecanora arctica Lynge]
Aspicilia arctica image
Thompson, J., 1997. American Arctic Lichens: The Microlichens.
Thallus ashy gray, chinky-arcolate, areolae to 0.5 mm broad and to 1.4 mm when fertile, flat, depressed-convex or high-convex; cortical hyphae vertically oriented; hypothallus not visible. Apothecia single to rarely 2 in the large areolae; cortex of thalloid margin of radiating hyphae; proper exciple persistent, brown; disk black, concave, bare; hypothecium hyaline; epihymenium brownish to olive; hymenium 100-125 µm, hyaline, 1+ blue becoming red; paraphyses strongly coherent, not branched, septate but not moniliform, according to Lynge (1937), but more or less so according to Magnusson (1939); asci clavate but very sterile; spores 8, 15-20 x 10-14 µm. Conidia Aliform, straight, 15-23 µm.

Reactions: K+ yellow, C-, KC-, P-, I-.

Contents: atranorin.

This species grows on noncalcareous pebbles. It is known in Greenland and Sweden, in Canada from Manitoba and the Northwest Territories, and in a disjunct report by Magnusson (1939) from Nevada.